Where do you sell them at? Is there fee's like ebay?
Yes on average 8 weeks and I normally generate reasonable btc in that time. Sales come from ebay and similar markets. Fees are ok, you gotta spend money to make money.
The real annoyance is the maintenance and driving around. I might drive out to the mine just to power cycle a miner, or swap a PSU (this happens a lot) or install new miners which usually takes some time to configure.
I might drive back to where ever I came from only to find something got sold so I then have to drive back out again the next day.
By far the worst is missing a delivery of new miners and then having to wait a few more days for them to get returned or drive to the delivery depo which is always no where near the mine..