Deal Buyout

Jumping ship to start own firm here soon. Focus in MF, 200+ units, mostly suburban/garden type. Coming from retail background but have experience on MF side and bringing on partner as well as backer (equity and deal maker from MF side)...current firm has a deal under contract (250+ unit, cannot come out of ground quite yet more of a land play). This is not exactly their cup of tea so with me leaving to start my own i can take deal and i dont think they actually want it but are playing it like they may take it through entitlement. I have some scenarios in mind to by them out.

1. We can go 50/50 on predev/entitlement to get to point where we sale or develop (can be 80/20, 60/40, however much they want to plug in but i want control and will do work. profits fall same way and can be rolled into land contribution on dev. side

2. We have spent about $80K plus a 50K deposit, still in DD. Reimburse them for cost spend so far and take full control. I offered them $160K (double up $ to get out, nice return) but they refused. Their thought is they dont want to miss out on the arbitrage if we can entitle and sell and create value. However I don't want to give them a huge chunk of that if they are all the way out. This could be a LIHTC deal or market rate, depends on what angle we work. 2-3 phase so fee's could be great. In this scenario i struggle giving up even more than 5% of deal to them for nothing. Have not created value, only have under contract.

3. 3rd scenario, they keep their $80K in and i need to spend about 200-300K more to get to a comfortable point in entitlements to get school seats. Here i could maybe give up more of the deal as they are carrying some risk with me.

Have been here for 7 years so have a great relationship with them but i think they are valuing themselves too strongly here. Any other developer would play chicken and wait for them to drop it. Yes, they have provided all the upfront cost so far i have spend $0 but if i step in and take it it over and get them out, i don't see how they can justify taking 20% or more of me...they see think they are deserving of a chunk that i cant justify....any thoughts on this?