2003 F150 xl V6 140k miles: New engine or bail?

I don’t know much about cars and less about trucks. I need a pickup, but only
drive it about 3 times and 75 miles / month. 10 ft bed pref, but I could squeak
by smaller. Just carrying lumber / home and yard stuff.

So I bought a 2003 F150 xl V6 with 140k miles from some guy on Craig’s list
for $3k. It is pretty much ideal for my purposes in every way and has been
working great for a few months until  it finally just gave out halfway to Home
Depot. I’ve talk to two mechanics. Both are confident that a head gasket blew
and bearings are messed up and both recommended replacing the engine.

Estimate: Used engine with 135k miles (and 3yr/36k warranty) + labor: $2,500

I asked both mechanics what they would do. They were both on the fence,
but one said he would try to sell it for about $1000 as is and go buy
something else. Other said he would fix it because I won’t find something else
better for less than $2,500.

Looking for advice / opinions. Fix or back to Craig’s list? What would/should I
buy to replace it if?