I found a one gallon jug of it for about $80 USD, a couple of summers ago.
I split the cost and oil with a couple of neighbors.
Much better way to get it if you can still find it in the 128oz jug.
Kind of a pain to search for a gallon of the oil because all the search results want to pull up those tiny, one-shot 1 gallon mix, mini bottles.
Shows as Out of stock, but Wally world had it listed for $75 USD here.
https://www.walmart.com/ip/Echo-Red-Armor-High-performance-2-stroke-engine-oil-1Ga/199023294
I run all my equip on 3.5 oz oil to a gallon of non-ethanol fuel.
This Echo pb-500 blower has probably 20~25 hours on it since these pics were taken, so a bit early to call it for wear.
The carb is that funny air valve unit and the mid-range is pretty rich when you set the top speed rich enough to not run lean.
I always let the blower run at idle for a couple of minutes after a full throttle run.
The cylinder has been wiped dry, but the oil in the bottom end is just how it looked when I first pulled the cylinder.
It has three reed valves (case induction for air/fuel and strait air injection to the transfer reeds), so it was kind of an odd duck for Echo to make.
The insides looked to be a bit cleaner that when I first got the blower (used) from someone at a yard sale.
I have no knowledge of what oil-fuel was run in it from new.
After this tear down:
I put a fresh ring in it (original one was a bit rough looking).
Also massaged the ports lightly and omitted the base gasket.
Other than a peek down the spark plug hole, I haven't looked inside of it since then.