I would suggest that buying good 2nd hand from a PnP vendor will give you signigficnatly better results than the low cost benchtops. Speaking from experience, having done both.
I will agree, as I have done on numerous P&P threads.
There are a lot of similarities between CNC machining and P&P (I do both). Some important ones.....
1. It looks easier than it is.
2. The small, low-cost machines tend to be more difficult than full-size commercial machines.
3. The critical little details pour in at an alarming rate
4. However long you think it will take - multiply that by 10 or more.
Printing is hard.
Setting up is hard.
Proving the 1st PCB is hard.
Re-Flow is hard.
Organizing the parts is hard.
Organizing the process is hard.
A reliable and easy to operate P&P machine itself is only a small step toward assembling PCB's. If it is fiddly, unreliable, difficult, or otherwise has some critical limitations - it can be a huge step backward.
If your PCB's are very simple with a small number of big parts - a benchtop machine can certainly be a useful option. If you are expecting a large number of unique parts or small parts - it gets difficult quickly.
Think about the smallest passive you would like to place.
Think about the greatest number of unique parts you will have in a given design.
Think about how much time you are ok with switching from one design to the next. A larger commercial machine can hold a lot of parts. On mine, it is usually set up for 3-4 different designs at any given moment. It holds about 120+ parts which I thought was ridiculous but I keep it full all the time and it is awesome. Very quick.