Hello NARDC,
seed selection is tricky, any variety of crop has various number of seed types.
so it depends on your resources and practises.
talking specifically about capsicum, i have grown Syngenta (Bomby - red & orobelle - yellow ) and Namdhari (NS280 -red & 281 - yellow) and syngenta paladin for green.
namdhari is about Rs.10/plant (red,yellow) & Rs2/plant (Variety Indra, Green color), syngenta is about Rs.2/plant(red,yellow,green)
thats about the cost part, including germination in my region.
about green if i compare Indra & Paladin (both are green varieties), i am a paladin grower, and i have tough competition from Indra growers (Yield Wise), but is more prone to dumping.
so that is all i know about green.
about yellow & red, namdhari has better yield, is more resistant to infestation. i’ve had cracking issues with syngenta, but i took special care, and it was taken care of.
so there isint much i could get. i can grow any variety in my polyhouse, but then each variety has different characteristics, some can tolerate high temperature, high water in soil, humidity, infestation etc. so the practise will change a bit once i get the grip of it.
i’ve had a friend ship 200 capsicum seeds from US, and sadly none of them germinated 
but then i dont stop, i still am asking friends/ seed companies / research institutes all over he world to send me all the possible varieties of capsicum they have.
if you are looking for Organic certification / produce, u’ll have to look specially for seeds grown/treated naturally. i too am in the phase to procure these seeds, so i am doing a lot of homework for their source and technical details. will let you know as i progress.
about online order and shipping, you’ll have to check with the companies sir, as they have their own shipping policies for quantity, location etc.
apart from this, consulting the local growers is the best habit, as they can guide you better.
if you are looking for more specific information, plz do tell, so we can try and find it, and i’ll get to know your point of thinking.
Vivek