domo house
dometo little house
domego big house
domaĉo dirty house ( I am not sure )
dometaĉo .. ugly little house
domegaĉo big ugly house

you can create words like that ..

Basically, affixes modify the entire word they're attached to. For example:
arbetaro = a forest (= group of trees) that has small trees
arbareto = a small forest (= group of trees)

Note that indeed domaĉeto can mean both "a small bad house" or "a purchase of a house" - if context doesn't explain the meaning, you shouldn't use this word, but dometaĉo/aĉeto de domo depending on the meaning. There are some other such ambiguities in Esperanto (respekti, kompreni, paperaro, intima are some examples that come to my mind).