T3 outclass most HACs. Recons are better at what they do but can’t really range tank since people usually flight or a wh ready to follow or on site under sleepers fire. In those situations, an ecm tengu will be more useful than a falcon. They are still used, but not has much as you would think.

Before you build anything, use a production tool like Evemeep to check build costs, and also look at where you’re going to try and sell your goods. A major hub will yield faster throughput but lower margins, whereas a market hub (other than the big ones like Dodixie, Amarr, Rens, Hek and Jita) will result in slower sales, but usually better margins.

Also, keep rotating what you’re making. Although I tend to invent so that I have blueprints for between 1,000 and 2,000 T2 modules, I only produce maybe 100 or so at a time before I switch to a different module for a couple of days. By rotating around maybe 4 or 5 things at a time I almost always find my sell orders completed before I take more of the same thing to the market. Just today I’ve taken 1.5 billion ISK of T2 guns and launchers to Jita and half of that has already sold within 3 hours.

Basically, I always look at the table in the market window for that item. I check how many have sold each day for the past 2 to 3 months, and how the price has changed during that time too. Then, when looking at the number of different sell orders already in place and volumes available, I can judge how many that market can stand me putting up for sale, and also how fierce the competition is likely to be. Sometimes it’s worth holding your stock for a few days as prices can jump and you can then make 2 to 3 times the profits you would have made if you’d put the sell order up earlier.

Hope that helps a bit.