One thing I would say is if you aren't used to using spreadsheets & you aren't well organised then I probably wouldn't go down the self SPP route as juggling 300+ buys & sells isn't that easy unless you're only going to do a few at a time. That would take weeks.
Bear in mind that you need far more capital on your account to buy the shares than the eventual cost of setup. My 147 shares cost $14,227, proceeds $12,404, net investment $1,823. I ended up putting about $6,000 on my account to do this fairly quickly.
To limit the spread loss I put limit buy orders on the bid side for each purchase (at one point I had 30+) & then once they are filled immediately put in a limit sell order in at the same price (again 30+ at one point). If you're lucky you sell immediately at the same price, if you're unlucky the price keeps falling & you miss closing out. Out of the 147 I bought I still have 7 left with open close orders, if I closed them out I would lose approx $21 on the spread. I did however make $14 on the spread across the other 140. I guess it depends if you need the excess funds back.
The one big advantage with IG is that you can do real time funding via a debit card & withdrawals free at any time.
