per plant has too many variables... you can grow a plant to several different sizes.
Figure 50g/sq ft is a good goal for from-seed gardens. If you get clones of a monster yielder, you can push 70g/sq ft. The genetic diversity of seeds will almost always give you a dud or 2, depending on sample size. If working with 1 plant, that's a different context.
Strains.. shit so interbred or what constitutes the same strain from another breeder might just be a distant relative. I'd just avoid the ones tha toverprice their seeds, like anesia, and find a couple breeders you are happy about the plants you've grown from them. I spent a bunch on inhouse one year and despite having good plants, it's definitely not worth the premium price they sell... a bunch of fools are happy to pay it so the rest of us get raped. The only way to get decent pricing is to not pay the ones taking advantage of consumer's OCD tendencies. Gage group is even worse .. those fuckers can eat a dick, lol.
What method is best for you comes down to personal preference. Can say that soilless is probably the easiest learning curve, if you start from a good point and not caught up in bro-science magic. When you control 100% of the plant's diet in a pecise way and can make easy formula adjustments that take effect almost immediately, it's easy to work out a really good formula for your local variables in a short period of time (short learning curve, limited trial/error).
buy bulk fertilizer - dry. You'll save 1/4th to 1/10th of the cost of overpriced marijuana brands. 4 cents per gallon is a good price. Brands like AN are 12-15cents per gallon mixed or more? that's a fucking joke, but they aren't even the worst offenders, lol, i just like shitting on AN for funsies.
check out guides and articles at cocoforcannabis.com for best info with least bro-science corruption. Also, keep things simple your first several grows. From a baseline from multiple strains/seeds and then try any of the "magic" you have an interest in... you'll be better equipped to recognize when it does absolutely nothing for you... rinse and repeat.