Pondering the old N+1 issue

You could buy something like this:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=171327411457&ssPage...

Looks legit, the seller is easily found on twitter/google.
https://twitter.com/Rob_Ward91

and build up the rest of it yourself. I have learnt to change everything on my bike over the last couple of years. The only thing I've not changed is the front derailleur. A bottom bracket can be scary but it is surprisingly easy when you have new components and they just click into place.

I would also recommend buying some tools and doing as much if the build yourself. There will be things you won't know how to do, but youtube tutorials are abundant and helpful. There will be things you lack the tools to do, those things you can outsource to the LBS, but in my opinion: The satisfaction of the build comes from putting it together bit by bit from start to finish and knowing it was your hands that did It. Plus you get the benefit of added mechanical know how, saving you future cash

now I love a custom build as much as the next man who loves a custom build but before you sell 2 perfectly good bikes in order to fund the assemblage of another slightly more perfectly good bike you might want to ask a few questions of yourself.

What are you hoping to gain from the new bike? More speed, comfort other performance upgrade? Will it make a significant difference or is it just that you fancy something fancier (nowt wrong with that)

What do you want to gain from a custom build that you couldn’t get from a good off the shelf bike with some minor part swaps? Especially since someone else will be building it for you.

I don’t seek to discourage you at all, I just think it’s worth checking why you want to scratch the itch and be clear about it. I’ve built a few custom bikes and the main reasons are because I enjoy the buying and selecting parts and then the assembling itself. The bikes have not been significantly better than I could buy from the shop, nor significantly different. They are a little bit cheaper but not massively so since I don’t have the advantage of bulk purchasing discounts. My own angle would be that if you want to build something custom then invest some time and money in tools and do it yourself, then you get something that is genuinely personal.

blue door cycles in crystal palace offered to build my bike up for around £80 if i provided the parts. The cost goes up to around £120 if they had to take components off another bike.

In the end i decided to buy around £60's worth of tools and have a go myself which was more fun, and a good way to learn how to fix bits on a bike.

My LBS is always keen to do a 'build/custom job', as it is a change from getting bikes out of boxes and merely fitting them to clients. When I researched the option for myself, my LBS was prepared to do a flat rather than hourly rate. Suggest you take a box of biscuits and coffees in to your LBS and ask! (I drop some jaffa cakes into my LBS every so often as a thank you for the support they provide.)

LBS's seem to charge in the region of £35 per hour of work in my neck of the woods, so it'll depend on how long it takes them to build it.

If you're going to sell you bikes to build a new one then at the very least that is N-1 maybe N-2 or worse

Seriously, why not ask the LBS is they are interesting in building your bike. I can't think why they would be offended; the worst they can say is no.