I have a surge tank.
a member here sells a nice looking one with pump I believe in your budget.

I have not seen an in tank one with the baffles etc necessary for an efi pump for much less than 400, but if you found one, I would go that route.

I would not be so concerned about road side service.
I had tried to plan for that with the surge tank.
Carrying an extra spare pump and hoses so I could bypass the system if I needed to. But really it wasn't something easy to do, even in a parking lot.
And you could do the same really with a second inline pump if you had to, surge tank or in tank just to limp it somewhere.