If that's all you can budget, you can't afford a 45' boat. Not gonna happen.
You can probably get a 30-35' fiberglass boat in fairly decent condition for that amount of money... and if you shop around, might even be able to get one that has been out bluewater cruising, and isn't in need of much more than a bit of updating...
Pros of getting a 30-35' boat over the 45' boat.
1) You can actually afford it
2) It will be easier to single hand
3) It will be more affordable in the long run—dock/slip fees, maintenance, etc.
4) Fixing stuff on it will probably cost less
5) It will probably be a bit simpler to use/repair than the larger boat.
Cons of a 30-35' boat over a 45' boat
1) It's going have less living space
2) It's going to sail slower
3) It can't carry as much stuff
It all depends on your priorities. If your priority is getting out there and cruising... get the smaller boat... once you're out there, you won't care that it is only a 30-35'... people have done this for decades... it has only been a fairly recent thing to see the average cruising boat size climb up beyond 30-35'. Look at Larry and Lin Pardey... been out there for years...and their boats have all been relatively small ones under 30'. Webb Chiles has been sailing for decades, and his largest boat is 37' LOA IIRC.
BTW, IMHO, if you and your partner can't live on a 30' boat together, then a 45' boat won't cut it either... boats are just too confined and small a living space when you're out there.
$50,000 is my total budget I don’t want to have to save for more than that. Sailing experience non, my sailing partner has the experience.