I would look into doing the foundation work and the bathrooms. Most buyers balk if there are structural issues, with a foundation being a major concern. Re: bathrooms, I would have your agent come in and give you counsel on what he/she is seeing in homes these days. Just keep it neutral for the next buyer. You don't have to spend alot, but for the bathrooms, they do need to be nice and of a cohesive design and color.
Without knowing the extent of what needs to be done, if you are finding it unaffordable for yourselves to do, keep the quotes from the contractors you have had in, so that these numbers can help price the house when you go to sell it, or can be used for negotiation purposes during the inspection contingency.
Consult with a Realtor, look at your potential competition.
You need to spend wisely. Your goal is to
#2 sell at the most net profit
So a Realtor can help you identify your priorities. it is too hard from this distance to give you the advice you need. It is a good thing for you to consider and I appreciate your wisdom in asking this question. Thousands of dollars could be on the line....
I had a client redo his kitchen completely before putting it on the market. He'd lived their for 20 years and his wife nearly divorced him over it!! Here she cooked every day with some funky electric range with orange counter-tops, dark, walnut cabinets, fake brick backsplash, and here comes hubby putting in stainless steel appliances, granite counter-tops, custom flooring, backsplash, viking range, etc!! JUST TO SELL IT! This all had a happy ending. We sold it over asking price at a price they BOTH couldn't belive and he ended up delivering to her a brand new shinny BMW roadster as she walked out of their favorite restaurant!! Yes, pay-back is good!