The last machine you brought was in 1978 - so for the last 37 years you have been thrifty --
Many active sewers change machines every 3-5 years as the new features come out....
so you have avoided spending money on about 10 machines.
You are still working and can ask the BL dealer what special financing is available, the company offers incentives and you won't have any problem paying it off before you retire, possibly without financing charges if it is one of the incentive times.
The next 37 years will be spent using a machine you adore! Why not?
Treat yourself. Being a thrifty person, you are not likely going to feel good about waiting until you retire and facing a large purchase then....
Remember that it is not a waste of money if you use it...sounds like you feel you will get your money's worth!
There's a whole new world of sewing and quilting and the Baby Lock is a fabulous machine to do it with! In joy, and Enjoy -- Marylou