I guess I'll add my experience to this:
DW and I always have a small beater, grocery getter as an extra vehicle. Currently it's a 1997 Ranger 4 cyl, 5 speed I bought in 2009 for $3K. Insurance runs $180/yr. Prior to the Ranger it was a '82 Civic I bought for $4K and lasted 6 trouble free years until vacuum lines under the hood starting cracking to pieces.
When weather permits I'll commute on my MC and she'll take the beater otherwise I'm in the beater and she drives her high mileage '05 500. My EB is not a DD even though 22mph is easily reached if you don't drive it like a race truck. I have found if you keep the tire pressure at 38lbs mileage improves without causing wear issues. The TVs job is to tow/haul and she will do it for many years to come, I hope!
As far as towing a heavy TT with the F150 EB. I had a 35' 9000lb Outback and it was not fun towing it due to sway and reaction to passing vehicles. I suspect the short wheelbase was the issue but never proved it. The FW in my sig is a perfect fit for it.
All situations are different but a cheap beater has worked well for us. However, I understand they are not readily available in the Rust States. Rule of thumb down here is do not buy a used vehicle that has lived in the NE.
