Look at used as an option. Apex and GHL can usually be found.
Open source, Reef Angel, is a nice product if you have some basic understanding of code. There are some things that it still does a lot better than any offering from GHL and Apex. This is specific to custom libraries that are not possible in either of the more readily available Apex or GHL solutions.
As also noted a 'pi based solution may also be there but similar to the RA I noted above. So the only other thing I'd suggest is make a pro/con list and consider upgrade in the future. That may help you navigate through the price and options. Today is just that, today.
Tomorrow, well, is just that tomorrow and we both do not know what is in store for us. If it holds an upgrade then waiting and saving may help you save money down the road. Best of luck!