I get the same way. I almost pee'd myself when I spent $80 on a naso a few weeks ago, and he didnt even live more than 4 days!!!
I spent another $70 on one and he didnt make it either so I am really really hesitant to try it again. Keep in mind I have established tanks and i still get nervous, but the majority of the time things work out ok.
Just keep an eye on your parameters, even things like temp and salinity, tangs get very very nervous very very easily. Stress is probably the easisit thing for them to suffer from and sometimes illness can follow so just watch him. Keep the lights off if necessary to make him feel more at home.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.