As a former realtor, the following is what you need to know that realtors, lenders and builders will NEVER tell you (the truth):
When it comes to new construction, builders don't care at all about you. They are just interested in closings and making a profit. Builders know buyers like you LOVE new construction so they can get away with charging higher "premium" prices for new built homes. You can never negotiate the price because builders know they can easily get another buyer in 10 minutes or the same day who WILL pay the builder's higher price. A builder just has to tell you, "sorry but if you want to negotiate the price, get out of here and I'll get a different buyer this afternoon." The only role the realtor plays is trying to negotiate the cost of upgrades. Builders will negotiate items that don't affect their bottom line (profits). You also need to know that the builder's contract is written by lawyers to benefit them - not you. It is NOT the same contract that realtors use which is state authorized. Therefore, there are terms in the builder's contract that you need to change and negotiate. Items like: if anything goes wrong with the construction, you need to pay for it. The same terms apply after you move in. If anything goes wrong, you need to pay for it.
As for Return on Investment - with new construction, owners need to live in their homes for at least 5 years in order to gain any equity / return. The minute you move into your new built home, it is NOT considered "new" anymore. Therefore, if you move within 3 - 5 years, your home will be compared to older homes in the same neighborhood. It cannot be compared to new built homes. Yes, your home will lose value the day you move in. Depending on the market in your area, it takes about 3 - 5 years to gain back the value you lost. Remember, the builder charged you a higher "premium" price to buy that new built home. Yes, you can call it a "gotcha" or a scam. I know it's unfair.
Now for the older 1976 home. Since this is an individual seller (not a builder), you have the freedom to negotiate the asking price. Depending on your market, how motivated the seller is and whether there are other offers - will determine how much negotiating room you have. How well maintained is this home? If you submit an offer, make sure you have contigencies for a general home inspection & roof inspection. Make sure the home is tested for insects, lead and radon. Make sure your realtor is able to negotiate the price after the inspection results. You don't need the seller to fix anything from the inspection. You can pay for it yourself BUT you want to lower your offer price. This way, you know the quality of the repairs since you paid for it. If you let the seller fix any repairs, you have no control on how well the repairs were done. You just have to take the seller's word for it and that is not good. As a realtor, I told my clients to lower the contract price instead of fixing anything. By the way, the repairs will be much cheaper than what you can lower the contract price for.
As for Return on Investment - you do NOT lose any value the day you move in. Since it's not new construction, you gain equity the day you move in PROVIDED your contract price is in line with recently sold homes that are similar to this one. If you overpay for this home and you need to sell within a year, you will lose value. What you need to do is review as many comps as possible. You need to see what similar homes have sold for within the past 6 months, homes under contract and homes that are still on the market (not new construction).
Finally - HOA fees. You need to know that HOA fees do go up. Why the huge difference between $360. and $425.? What do these fees pay for? You need to compare what each HOA pays for. Suppose in a year, the fees increase to something like $370. and $435. OR suppose one HOA fee increases while the other HOA stays the same. You need to ask EACH HOA if they have any capital improvement projects on their agenda that will increase the fee. You don't want any surprises. Also ask each HOA about their cash reserves. Does each HOA have sufficient cash reserves to handle an emergency? HOA's that are short with cash reserves will need to increase their fees in the event of an emergency.