I would not pay for ANY extra multi time. In todays market I would just get the multi hours that are required to get you through MEI. The extra X amount of hours will not be enough for anything and cost a TON of unneeded cash.
I was fortunate (sort of) where the school I taught at had a multi but they were sparse on students and they gave the twin time to the senior instructor regardless of who found the students or whos students they were. He left and I ended up being the next in line who met the insurance requirements and had the twin monopoly. Even then I only probably flew 30-40 hours or so in it but it was a start and it was free.
From there things were looking better and word started getting out that I was one of the few MEIs in town (new england is sparse) and I ended up doing a gentlemens commercial multi and MEI in his seneca 5 and then I ended up doing a little work for a guy in his baron which led me to his friend who needed a cfi in his 310...and then to a comanche...and then to a bit of part 91 work in a cessna 414...and you get the idea.
Getting my name out there and a little networking and then simply word of mouth brought me probably 100+ hours outside of the school I taught at.