Valuing lakefront property

[Mike Rutallie]

I am considering purchasing a "near" lakefront cottage that I believe is priced far higher than I would consider fair market value, but I may be looking at this wrong. Here is the situation

Cottage - seller asking $300K
Sold in 2021 for $225K, seller put about $15K into it
Built in 1940s, very few updates
Needs new roof, old 2-wire electrical, original walls, and has an $8K assessment by the association about to come due.
700 Sq Ft
Part of an association owning shared private beach access
@ $300K it is $426/sq ft

Comps (all sold in last 6 months)

Cottage sold (to this seller) 5 months ago for
$425K @ 872 sq ft = $487/sq ft
"Direct" lakefront property part of same association
Built in 1940s, some updates

3 other comps I've seen that are larger that have similar associations w/ shared private beaches that are "near" lakefront on the same lake.
1. Sold $485K @ 1552 Sq ft = $312/sq ft. Plus garage and fully renovated.
2. Sold $310K @ 1100 sq ft = $282/sq ft. Plus garage and partial renovated
3. Sold $488K @ 1200 sq ft = $373/sq ft. Plus garage, and fully renovated

My question is should I be looking at this purely based on cost/sq ft, or should I give a percentage value to the property it sits on, then assign a percentage value to the structure itself to figure out the fair market value? Or is there another way I should be assessing this?

For reference here is the breakdown of price based purely on cost/sq foot of this 700 sq ft cottage
300K = $426/Sq ft
280K = $398/Sq ft
260K = $370/Sq ft
240K = $341/Sq ft
210K = $300/Sq ft

The intent is for personal use of this cottage as it cannot be a short term rental.
I wrote a separate post regarding creative financing on this with the seller herehttps://www.biggerpockets.com/forums/50/topics/1171112-pleas... which may paint a little more color on the situation.

I appreciate the help.