i should chime in.....if you do the work, consider it a labor of love & do it to enjoy RIDING the bike...that way the $$ put in becomes rather moot.
I have an '87 LeTour that I really dig. I kept the friction drivetrain (for now), but use suntour bar end shifters, 105 brakes/aero levers & a moustache bar. You could do 9 speed indexed bar ends & find some pretty inexpensive modern wheels (=< $150 new, much less used) that will take a 9 speed cassette (=< $20 used with some Ebay luck). The wheels will likely be 700c, so you may be maxed out on stock brake caliper reach & need some of the Tektro longer reach road calipers (about $40 bike island). The 9 speed bar end shifters go for between $45-$75 on Ebay. You could end up wanting some new levers (free to $30ish). So, basically throw another $300 or so into it & you have "modern" convenience with cool old-school lugged steel....which you can buy new for maybe $2500 these days (albeit, a much finer build in every respect...but you don't find economy new lugged steel frames these days, right?)
In truth, my LeTour was probably about $150 total & it's a pleasure to ride....but I don't have to have indexed shifting to be happy.