I agree, or possibly "I, the buyer, should (or ought to) beware".
I think that means "emptor" needs to be vocative - if it isn't already - and "caveat" needs its 1st person singular subjunctive form
- I'll try to remember to look it up - I'm sure my wife still has her old copy of Kennedy's Latin Primer somewhere in the house (in the loft I imagine). She did Latin all the way to 'O' level and so graduated to the one with the red cover (swot!) - I only remember the one with the blue cover (same picture) and enough to strike terror into the heart of any 1970s (or previous) schoolboy.
On a not at all tangential note, this is a DIY group isn't it ?
Anyway, I'm definitely going to bed this time.
Gary.