Dropshipping is great if you get something that will sell and gives you enough return. You should get stuff for 50% when dropshipping. Good dropshippers provide catalogues without shop branding, PO BOX return address so you can whack your shop name on top of the address, invoices/receipts with your letterhead etc.
Ive also had trade accounts with people too. Generally they ask for an initial minimum order of a resonable size then lower min orders after. ie £500/100. The outlay, returning of goods etc is the worry.
Also sometimes things just stop selling. I had 1000's of resealable bags, envelopes, smoking papers, notebook left over from my selling days. Thy eventually go but I relied on regular sales.
I made most money from sex toys (!), resealable bags and dietry/body building products. I know someone who makes a killing selling organic growing mediums, plant nutrients from internet suppliers.
You would be surprised whats sells. I made £30 a day for a good year or so from 2"x2" resealable bags.
Checkout Alibaba if you want to take a risk. I know people to have made a killing by selling LAN cards from a site like Alibaba. They also used to buy cheap stuff off ebay and resell. Big money in buying old vans (10years plus... £500 jobbies) giving them a clean, MOT etc and resell. Honestly, big money!! ie My ibook was bought for £120 and I could have sold it for loads more.... double if I was lucky at the time. My dSLR was bought for £200 with 4 lenses.... every other similar auction was around £450-£500. Gold toothpicks slip by on ebay every now and ten for a tenner, resell for £100.
I never did any proper internet selling but made about £1000 a month on ebay.... and email. I used to email my old ebay customers offering them more of what they bought the first time from me... offer to do the sale on ebay and a good 10% of them would buy again.
Marble Tesserae for making roman/classical mosaics is expensive but stone mason will almost pay you to get rid of the waste they produce. Its easy to chop it up with a tile whizzer.
You could sell information. Useless info for a £1 on ebay... I did the dirty selling website addresses "buy a 52" Sony Bravia" for £20. £1 for the address and about 20 sales a day.
My stepdad sells "healthy living" info. He's got a website selling subscriptions to access Yoga/Pilates videos, articles written by dietricians and doctors hes contacted etc. $20 a month and a fair few subscribers.