Ya if you can get a good motor and a wing for $3500 I would do that, in fact if it’s actually a good wing and motor please send the link I would like to buy it.
not sure I can generate a link since I just viewed it in person during an extended training weekend: I reached out to my instructor for details on the engine and wing since I am new to this and am unable to remember exact model 
I guess if you are comparing used gas motors to new electric motors and you plan to only put around 10hr a year or something on it then ya per hour cost is not very good. But I think you have to compare new Eppg to new Gasppg to make a comparison right?
that’s completely fair: if I were comparing new electric to new gas then you are right that electric is competitive. I think I resorted to comparing new electric to used gas because there isn’t a big used electric market: I haven’t been able to find any listings outside of this forum. I wonder if there is market for used LiPos somewhere, where one could purchase heavily discounted batteries at the risk of them underperforming due to usage history? I imagine this is risky purchases
And if you are paying $1800 for each 45min flight ya that not a good deal. The cool thing is you can recharge that battery and use hundreds to thousands of hours over and over again for just less then 50 cents per flight. I’m assuming your not saying $1800 per each flight
haha, what I meant was “$1800 for a machine that can fly 45 minutes per session”.
but let’s say electric has higher initial investment (only necessarily true when comparing to used gas, which would be my alternative). this higher expense will be partially mitigated by the fact that recharging a battery is much cheaper than burning gas; however, a pilot will probably experience total system failure prior to the point at which purchasing and flying a new electric ppg has become cheaper than purchasing and flying a used gas ppg.
And also it’s not $1800 per 4kwh pack if you own or are buying an Sp140 it’s $400 less. We just half to make the default price higher because non PPG users were buying packs and I’d like to keep batteries in stock in a low price for openppg users. A coupon will be given if you’re an open PPG customer.
I saw the note about reduced price if you own an SP140 but it did not read to apply if you own an X4 which makes sense if they are incompatible. $1400 for hour long flight time is not too bad: OpenPPG battery comparison sheet lists $1800 of bonka batteries to yield ~45 minutes so this is definitely competitive, but I also believe I have read that for some reasons the SP140 is better suited for higher flight times even aside from battery capacity.
As far as using the Sp140 battery in the X4 the voltages are different, but I’m not against making an li-ion pack for the X4, it’s just not in the current roadmap. So no promises there.
I think I have read somewhere on this forum about people opening Tesla packs and reassembling so as to modify voltage of the pack; however, I am definitely not sufficiently experienced to comment or experiment with this 
I think the X4 has good potential to be really low cost, light option design for shorter flights where the Sp is designed for large power long flight times. The X4 will probably get a redesign also with a new battery option. They would come together.
yup, this is mostly why I am torn between X4 and gas powered. I love the idea of folding up the unit and packing it into my car without gas fumes, having to carry liquids, having to mix oil, etc. And most of the time I’d be flying would just be up to 30 minute flights in scenic areas to capture some video while traveling, as opposed to cross countries or long flights just for the sake of being up in the air for long periods of time.
Based on this, I pretty much just want ~30 minute flights for as cheap as possible, potentially with the option of buying multiple packs so I could do back-to-back flights instead of extended single flight. This is why I ask about golf cart batteries on another post, since battery comparison sheet lists them as pretty heavy and unable to be chained but incredibly cheap (relative to other batteries) to yield a ~25 minute flight.
I assume this is all speculative, so I don’t figure you have any timeframe or estimate for this “probably get a redesign with a new battery option”? Like I’ve said, I’m currently considering what I want to purchase as my first unit. And as you might be able to tell, perhaps I am putting too much thought into it but I figure a wise purchase will last a long time and not need to be replaced for years.
as I spend more time training I realize that most people who paramotor do not do it every chance they get but instead opt to wait patiently for ideal conditions. it would also be interesting to see, e.g. how the life of the battery changed over time of 1000 hours of usage. I bet that’s in the top 1% of gas motors too: I think a unit enduring that long would be pretty remarkable.