Main Venting 2 Pipe Steam
 

I have a 2 pipe steam system that is fairly poorly main vented. There are 4 pipe ends each with one vent thing. My Plumer/heater man says that I could help save some energy costs by adding multiple vents to each pipe, I don't doubt this because it takes over 40 minutes for heat to get to my radiators due to the air in the system.

My question is, is this something that I could do myself without much danger? I was quoted $100 per vent, and $100 for labor one time fee. The vents he told me he would be using are Gorton vents, which I Believe he said he would be using the larger models (No 2, 1/2" i believe). I found those for around $50 each online, and wondered if it was hard to plumb 2-4 on each pipe like he would do to achieve a max venting of my system.

Get multiple bids on the same job until the bids cluster together.

relative price
$0.....2.....4.....6.....8..
....a.....bcd.........e

The true price of doing your job today in your area is probably c.
a and e are definitely outliers so I'd have to wonder what spec's they were bidding on.