Many folks look at the cost,compared to a small charcoal grill,or even a gasser.[where fuel is expensive]
Many look at the the cost of two CS vs. utility of being able to cook two different products,at different times/temps.There are logical antecdotes for the multiples.[We're not talking about working cooks that know their specific needs]
The decision often does not move towards the double units.The ability of placing more slabs,on larger racks seems to win out.Ribs are the decider,since I can cook thirty lbs of pork, if forced to in the smokette.
Seems like all will comment,after the several years of cooking,that the cost per day[because it is so easy to use]rather than the cost per week,makes it negligible.
The grills ,after a very few years are usually at the dump and the CS is good as new.
A bunch of the folks here, were here to help start the forum,years ago,and seem to concur.
The fuel costs on a grill,and almost all other smokers, would be far higher than the cost of the cookers.
The CS,no fuel,repairs,parts,etc,except the initial purchase.
Asking all the owners,that had these same thoughts, that if you picked an initial price of $1,000,and only used it for 5 years that is $4/yr.
You can't buy the fuel for anything else for that.
This isn't a sales pitch to folks that have already decided to buy something Cookshack,but an old adage about what size and the incremental increase in purchase price.
Ask almost anyone around the cooking business and they will say"do all your calculating about what you need,and buy the next larger size".You will never regret it,as the years pass.
I used to hear that from cooks decades ago,and I hear it from experienced cooks today.
Just a couple things to ponder.