Engine Replacement Cost?

[TheGr8Ginger]

Sadly, I'm pretty sure my engines toast, as last I ran it (3+ months ago), it had SUPER foamy oil.  Noticed I'd be going through a gallon or more coolant a week often, so I'm leaning towards the water pump failure. I'm hoping somebody here's has some input on what I can expect when talking to a mechanic. I'm curious as to what this community would say to expect regarding price with either an engine replacement vs rebuilding the current engine. 

Realized I haven't given vehicle specs yet:
Year: 2013
Model: Edge SEL AWD

Sadly, I've also still got a loan on this thing (<$4k), and am focusing on just getting that paid off first, as my better half has a Yukon she's graciously letting me borrow. Just miss the mpg efficiency enough to FINALLY start doing some research into this.

Pretty sure I have a 3.5, but I'm a nerd not an engine guy, so correct me if I'm wrong. Outside of some better HP/Torque, would there be any benefit to swapping up to the 3.7? I mostly live off cruise control (+5mph speed limit at most), but occasionally enjoy feeling a little young again and putting a little bit more peep, so would the 3.7's power difference be that noticeable? If MPG is a noticeable difference, is it yay or nay with outcome?

Thanks for any input you're able to provide! 

[dabangsta]

Sounds like it probably has the 3.5, which was the standard engine for an SEL for that year. The 20 extra HP from a 3.7 could be appreciated but probably not as apparent as it seems. If the water pump/seal failed, and failed in a way to fill the crank case full of coolant and water, and it was ran that way, it likely needs a replacement engine. $3,000-$6,000 (especially with AWD) in labor to R&R an engine and replace the water pump and timing, $1500-$2000 for a used engine delivered, maybe far less if you can source it locally from a junk yard, especially a you pull it type place, but lots of additional work.