... so if I thought it was OK to get another week or so out of them then I would.
Well, in that case, I'd suggest care and attention to how you store suits you aren't wearing. It can substantially extend the period between necessary cleaning.
First, always, always "air" a suit before putting it away. Even a hour hung up in an airy space allows many odors (cigarette smoke, etc) to dissipate, and also, to not stink up the rest of your wardrobe. Remove anything bulky or heavy from all pockets before storing. Do up buttons and zips when storing. It helps the suit hold shape, and helps prevent fabric distortion. A suit should always have a quick, gentle brushing, or at least a going over with a lint roller, before wardrobing. Don't tightly 'pack' clothes into the wardrobe. Each suit needs to hang freely.
If you got creases, either in jackets or trousers, many fsbrics benefit from a light steaming. But I do mean "light". It's enough with most to hang them in the bathroom for 30 minutes or so after a hot bath or shower. Then, and DO NOT skip this bit, hang them out in an open airy space until all steam has dried out. For most materials, most creases will gave just dropped out if you do this right.
And if you collect specific stains, treat them carefully, and as quickly as possible. At all costs, avoid wetting then stressing fabric while stain-removing, though. And if spit-cleaning doesn't work, then dry-cleaning may be necessary and if you do dry clean, do it as soon as possible, use a good cleaning company, and point out specific stains when booking the suit in. If you don't, and they fail to spot it and treat it correctly, they can effectively 'fix' the stain by dry-cleaning without pre-treating, at which point, the stain is permanent.
Bear in mind, dry-cleaning consists of washing your clothes in some quite aggressive chemicals (usually perchlorethylene), and that process alone will degrade suit fabric, so over-cleaning can be more damaging than not cleaning enough.
The biggest trick is in the airing, usage rotation, and considerate storage.