i created an alt to do engineering , now at level 35 but with all the farming you will do collecting ore you will not make millions of gold but my alt just has 150g and a full set of netherweave bags , probably enough mats in the bank to be worth around another 300g .
if you are not in a mad rush to level but want to have some fun , engineering is a real good way to go , i would suggest to be able to get any use from the toys you have to start around level 10 and just keep engineering to your level , buy any reasonable priced gun/sight recipes you see as i can sell guns and the better sights quite easily , also as i made a hunter the free bullets are a real bonus
i am not sure what class would be best to be an engineer as a lot of bop stuff you create is cloth ,
best first fun i had was at level 30 with the harvest reaper kit , its a robot that is level 35 and does a great job in defence , i found when it dies you can loot it and most times get a lot of parts back
there is also the goblin jumper cables which are useful if you are not a class that can bring dead players back to life ,
so much fun in engineering to be had with bombs , robots and other odd stuff , as long as it is done with care as you level you will slowly make some gold , and of course at 70 you get the flying machine which has to be worth the long trip to 70 as there are still so few about on my server