An extra lab costs 50 points. Someone has agreed to give back his 25 points already, so if the group approves that could go towards an extra lab on top of the free lab everyone gets.
I'll be honest, that's not the best way to spend those points though.
Here's an idea though. You could buy a spell casting tablet of 'The Laboratory of Bonisagus', Cr Te 45 Ritual (Covenants page 122) for 18 build points, and then spend another 2 build points for the 9 pawns of Vis it costs (you'd have 1 pawn left over) and literally have a very functionable lab with the casting of the spell. It's cost in total, for the vis for 8 labs is 72 pawns (8 labs times 9 pawns per lab), or 15 build points (1 pawn per 5 build points, for 75 pawns of vis), plus the 18 for the casting tablet (2 points per magnitude of the tablet). A grand total of 33 build points, I'd be willing to allow the PCs to each contribute to this total if that's what they wanted.
Drawbacks, that's a ton of vis (likely to be all Terram), the spell would still have to be cast 8 times (even if Agitatus casts it, there is risk). Finally these labs start off with a high upkeep, which could either explain or just be one more part of the fact that you're poor. It's not the best idea maybe, but it's just the type of thing a young group of Magi might make (basically maxing out their credit cards).
The advantage is that you start off with superior labs. You can literally say that your entire Covenant, labs and all, was truly constructed Hermetically (it could lead to a prestigious reputation). Your lab is ready in only one Season (the spell more or less takes care of it immediately, but it takes a Season to attune yourself to it). You would also still have the lab text should you need to build or replace a lab later on.
What do you think?
For ease of reference, it builds a lab with these stats:
Size 0, Refinement 0, General Quality +2, Upkeep +3(!), Safety 0, Warping 0, Health +1, Aesthetics +1
Specializations: Items +2, Vis Extractions +2, Creo +1
Virtues: Flawless Equipment, Flawless Tools, Spotless.