It really comes down to whether I'd make my money back, or at least not lose too much on the deal. At the moment I get:-
frame - free
forks, headset, spacers and stem - £100
Midge dirt drop bars, v-brake drop levers, v-brakes bar tape and BB - £80
wheelset inc tyres etc - £200
chainset, pedals, chain and cog - £60
saddle and seatpost - £40
So I'm looking at £500, I could probably get that down a bit to maybe £350 with patience.
Yeah I know, I think I'm set on doing the SS/Fixed conversion so it would need a new rear wheel no matter what. As it's 126mm spacing that shouldn't be too expensive, i reckon I can get one for about £50. The rest I can probably cobble together for a lot less. May just leave it with 26" wheels, whack on some v-brakes and levers I already have, new headset and BB I can get for about £30. All in I reckon I could have it up and running for about £150, depends on how successful I am messing about with cones and bearings etc. I was initially going to put new bearings in the BB as the axle isn't pitted but I can get a cartridge one for under £10. Let's see:-
keep f&f - free
BB, chainset, chain and cog - £50
headset - £15
rear wheel - £50
front wheel keep existing - free but may go for a complete wheelset deal
bars and stem - keep existing
brakes and levers use what I have - free
saddle, pedals, tyres, tubes and seatpost, use what I have - free
cabling - £10
So complete bike for an actual outlay of £125 maybe up to £175 allowing for full wheelset - reckon I could recoup most of that on a sale.
One thing I have noticed, due to the mass migration to disc brakes and stans/tubeless, light quality used 26" rim-brake wheels are now going for a song (i.e. less than 1/3 of new prices). You just need to spread your dropouts by 9mm.
Why 700c front? If it was an mtb are you sure you can get your v brake to reach a 700c rim?
If going fixed/ss chances are you will need different length BB. If you have an old one that you can put on for now, sort the rest of the drive train out, then figure how much you want to add/subtract.
+1. Or it might be cheaper for you to use a bb you have already, and add/subtract spacers behind the rear cog, and/or move washers on the rear axle, to get the chainline right.