Your best bet is to show that higher authority how well you can manage extra responsibility. Take on an additional chore without that authority asking you to or demanding it. Do it well and with regularity.
If you are on your own as far as funding goes, and the higher authority is okay with you adding another enclosure you may consider putting together a very nice one bit by bit.
If additional chores are few and far between, better grades in school seems to work well in the minds of most authority figures.
If you happen to be a high performer in school already, ask yourself what is it your authority figure has advised you in the past; often authority figures really do know whats best in so far as the who, what, when, and where in your life should be.
In the end, authority figures are just that, respect their wishes, but if you take up a new chore, improve your grades, or take some advice to heart, keep up with it even if the authority figure remains against your choice of gecko. Your doing it to gain more respect, the secondary gain might just be an okay from that authority figure.
Maurice Pudlo
AKA: Authority figure to 2.2 ranging from 20-12