RE: Large capacity inverters and bad cheap inverters
For our purposes, in Vanagons or Vanagon Westfalias, the best bet is to add
12v outlets and use 12v adapters for as many of our toys as we can.  Only
go to the inverter if absolutely necessary.
That said back to the original question on inverters.  IF you have a big
beefy aux battery or batteries and IF you really need a lot of watts  then
plan on spending the money (big money) for a good brand name inverter.  But
if you needs are in frequent and not a lot of watts then you should be able
to get by with one of the smaller and cheaper Brand X inverters that are
available all over the place from marine supply, RV stores, sporting goods
stores, eBay, etc. About eight years ago I picked up an inverter that is
rated at 400 watts for $39.95.  It gets limited use (mounted behind the
driver seat) but has been put to the test a couple of times with appliances
that were drawing all of that 400 watts and then some and it's held up.
Summing up.  If you really need an inverter for continuous or heavy load
and you have the aux battery capacity to handle it then spend the money and
get a bit brand name inverter.  But if it's going to be casual or
occasional light use then go with one of the cheaper smaller inverters.  If
it losses it's smoke and quits then just get another one.
YMMV