Selling contingent upon buyer's home selling

[Jonathan Kelly]

Hi everyone!  

I'll try to keep this as short as possible:

I am a part time agent and investor.  I bought my first flip in Dec of 2015 for 58,000.  I lived in it and fixed it up for a year (put roughly 16,000 into it) and put it on the market at the beginning of the year.  It's had lots of showings and good reviews but no actual offers (probably priced a tad high).  I just got an offer from a couple I met at an open house.  They seem like they are solid and I googled the house they're selling and they can definitely afford mine.  My house is listed for 129,000 but it's probably worth 117-123.  They offered 115,00, and I pay 2500 (net 112,500) in closing costs plus they want to wait until their house sells.  obviously the offer is a bit low and I can negotiate more money but my question is:

Should I sell my house to this couple who are very solid buyers (they're also putting $23,000 cash down payment) contingent on the sale of their house?  If so, would you suggest I put a time restriction on there (say 4 weeks), that let's me have an out? Anyone out there with experience in this area or ideas?

Any help is appreciated!  

Thanks!

Jonathan