Depends on your comfort and how much needs doing. I think, if you love this house and would regret not getting it, get it.
YY to:
- The trustworthiness and competence of tradespeople will make or break, so go via word of mouth.
- Everything takes longer and costs more than you'd like to think it would.
I'd also add: budget in some "me/us time". It's easy to get so wrapped up in renovations that you neglect yourself or just having fun from time to time, esp with your wee ones.
We've just moved into a bit of a building site. We [now] have heat and hot water, cooking facilities, a working bathroom, but the only room that's "done" is DS's - we made it a high priority because we thought the move as a whole would be more jolly for him if he had a lovely room to move into, and we thought this would be a sanctuary for him when we do work elsewhere around the house. NB the latter is only a partial success; he still gets lonely and wants to be with us. So, another thing we had to "budget in" was the occasional day out, or playdates with his friends.
He's 4.8 by now, though, so is able to understand that he's not allowed in certain places. Also, he loves helping with things! Especially scraping all the dreadful wood-chip off the walls (and actually he's quite good at that - want to borrow him?)
We always thought our next house would be a fixer-upper - we can't afford otherwise! We love the idea that we're adding the value to the property. So for us, that's the decider, everything else is just what's needed to make it possible. YMMV.