I have a post (see link below) that challenges conventional BP wisdom of DIY only.

If you install salt system and automatic cleaning your maintenance will be fairly low.

L.I write about No Bank No Credit financing.If you want to play in the sandbox of no money no credit, you need:Private Lenders (knowledge of self directed IRAs)JV Partners (splitting profits w cash partners)Creative Financing (sub2, land contracts, installment sales, TIC contracts, using notes, etc)I used to live in Mt Kisco, Westchester.I get what you are trying to do.Good luck!

Installation is free for normal rooms.

Nope and don't accept the SD in installments either.

There probably aren't that many investor buyers in Spearville and the installment sale would spread the income tax burden for the seller.

It appears to be on a reservation because the Bureau of Indian Affairs is involved, @John D. and it also appears that that it may be a contract for deed (land contract, installment sale contract) where the seller received full payment over time, but never transferred the ownership to the buyer even though it was fully paid by the end of the contract. 

I don't see why you're prevented from installing a lawn this year?

I would check with a local HVAC (Hydronic) wholesaler or installer to see if you can still obtain them {be prepared for them to cost almost the same {probably more when you factor in labour} as replacing the entire unit.As for using PEX, I'm not certain if the heat-rated PEX (used for in-floor hydronic heating which runs around 140F) can be used for a boiler and radiators (which typically run around 180F).  

A small time operator, DIY guy, with a W2, if you had it back on the market within 90 days I would say you would be doing pretty well.