I feel for you noel - I hope you can get it sorted quickly.
My theory in this situation is :
A) it's worth nothing as-is, so you may as well fix it, and
B) once fixed, you've got to get your value back, so you may as well keep it for as long as you can.
Personally, I'd be looking at a reco motor. I wouldn't muck around with fixing your current one, especially if you can't DIY. Every dollar you spend on pulling the current motor apart and inspecting the damage is money you don't have to actually fix. If it did get hot, then I don't believe they're ever really the same afterwards. Personally, I'd pull the current 2.8 and swap a "new" one straight in.
Cheapest and quickest is to pull 2.8 out and put 2.8 back. If you want to upside, you can pull 2.8 and put 4.2 back, but then you're going to need to do a lot more work, and spend a lot more coin. Which means that you'll need to keep it even longer to get your return on that investment. If that sounds like a good idea to you though, then go for it.
If you can DIY then the above changes, so long as you value your time at $0.hr. You can pull it apart yourself and replace what's wrong, and get it back together in a better state for less money. But if it is your daily, the need to get it back ASAP might be your overarching concern.
Good luck - it's not the best place to find yourself!
Matto