Dan, In the end it all worked out. I was 59 when I received the retirement package, which was generous, but not overwhelming. The better deal was that I immediately started working at the same company as a contract engineer for one of the guys I had worked with on a similar project a few years earlier. That lasted 3 years. I then went to work with a competitor at an entry level position, but we decided to hang it up when I had to get my knee replaced at 63.
My layout is like yours in that I bought very little lumber to build it. I used what I had on hand, what I removed from my dad's shop when he and Mum moved to personal care, and some I removed from my mother-in-law's house. What I couldn't use I gave to our younger daughter and her husband to build forms for new cement steps. I bought a little used GarGraves track, but most of my track and Ross switches are new. I don't need as much as you will. I have used bridges and a few used buildings. Most of my engines and cars were bought used as well from Forum members. That sure did stretch the hobby budget. I had spent all the money I got from selling my HO stuff on tuition for the daughters 10 to 15 years ago.
I hope you will post some photographs of your progress. As you can see from my Blackwater Canyon Line topic, I have posted the Good, the Bad, and the Ugly. LOL