That is quite the feat. I would not be able to find anything decent for less than 1000 euros. I would also have to say that I live in France and that economic circumstances aren't really the same.
Nonetheless, I still stand by the fact that if the La Spalla is a perfect fit, I would not advise MTM - what's the point? As Timotune specified, there are loads of great features to the model that outweigh those of a basic MTM.
As for sizing, I'm between a 36 and a 38 and I chose a 38. I didn't alter the jacket at all. The only issue I have is that the collar is too big - but I have a small neck. I could minimise this by having it altered but, oh well. And no Monkeyface, this wouldn't be a reason to go MTM!
No worries, we each have different standards. I'm quite the perfectionist, so any flaw starts bothering me after a while until I simply stop wearing the garment. This annoyance is multiplied by the amount of money I paid for it, i.e. the more more expensive it is the better I want it to fit. That's why I would go for MTM around 500/600GBP. Luckily most suitsupply suits fit me incredibly well, so it has kind of become my go to brand.