Here are several bathroom sinks for sale.
The first one is a used little plastic sink for an RV or small space. with the drain attached. $10.
The second is a used ceramic vanity top to go on a 24" vanity base. It is 18" deep and 25" wide. and has a faucet, $40. See photo above.
The third is a used plastic three hole drop-in sink for $15. For somewhere where a ceramic sink might get broken.
And the fourth is a NEW expensive ceramic under-counter bathroom sink, 19" x 15". Reduced to $30, these cost many times that at the store.
The fifth is an 18" round sink, with drain, that can be used above, or inserted into vanity top. $30.
Thank you for looking.