If you do NOT trade your car in - you're simply dropping the keys off - there's a $300 lease disposition fee. The only way it really comes into play is if you're NOT getting another Subaru.
If you drive more than 15,000 miles per year, then you want to buy your car. If you drive UNDER that, the sweet spot for a Subaru lease is 36 months, and 15/12/10 k miles per year, depending upon which you choose. For us, 10 k was too little, so we got 12 k. Note that leases end up being a little state dependent. Down here, for example, I have to pay TT&L up front, but there's no other fees involved. Other states have other fees, so your results may vary. Standard rule of thumb on a lease is figure out what the 72 month payment would be. Then knock about $100 off that. My 2019 Forester is an option 32, I stuck another $1,000 worth of accessories on it, and I'm paying just under $325 per month for it. (It's a $35k Forester.)
The neat thing is, since the residual value is fixed at the start of the lease, if I decided to purchase the car at the end of lease, all I have to do is pay the residual value. Either refinance it, stroke a check, or whatever. Or trade it in. It'll be worth as a trade-in about $2k more than the residual, that'll cover my TT&L, and I'll get a new car. When I finally get ready to retire, THEN I'll consider buying, because at that point I'll keep the thing forever.