I think this one really depends on what the goblin is doing or how well known they are. A goblin who dresses poorly but is very, very well known for their riches can likely get away with it, but only because others would know they have the money to throw around getting whatever they want. Another goblin who is not so well known but dresses very well may get into places their class status and funds would not otherwise allow.
Goblin social structures are likely based on a mixture of appearances and acknowledgements. A gob either needs to look rich, or be so rich people know they have money. Even a goblin that could go swimming in gold might get hassled and harassed if they look broke if they’re not well known… at least until they show the gold off and buy some respect.
A mixture of both would be far more valued in goblin society than either one or the other, but the appearance of wealth would be necessary to garner the utmost respect of a gob’s peers. When it comes down to it in the end, even a rich gob who dresses poorly might run the risk of people thinking they only have money because they’re so stingy they can’t afford to waste even a copper… and that’s as bad as being broke already. If you can’t afford to blow a little gold looking good how much can you really have to spare?