Depends on your needs and expected volume of business. I use a godaddy/wwd reseller plan mostly to register my own domains, and by my calculations I would have to register/renew about 250 domains per year to make it worthwhile (compared to other reseller plans, eg resellerclub which doesn't charge an annual fee like WWD but have higher buyrates esp for lower tiers/slabs - i also hate the resellerclub control panels). If you're going to use the standardized shops then WWD will be easier to setup than resellerclub. The fees for godaddy/WWD regular and pro reseller plans are the highest if you buy from them directly ($99 and $199, respectively) and lower if you buy from a "super" reseller who can sell the godaddy/WWD regular and pro plans at a discount (~ $60 and $140 with slight variations depending on the promotion that the super reseller runs).
Enom's reseller plan also requires an annual fee with slightly higher buy rates than godaddy/wwd but some ppl like the enom interface. Most ppl get the enom reseller plan b/c they don't want to pay $30 retail for a domain, but you can bypass that simply by registering an account via one of enom's resellers like the namepros forum (I'm not connected in any way with namepros) and pay just under $10 per reg. Also helpful for taking pushes at enom. Personally, i dont like enom and besides that i get my best rates at godaddy or my reseller account with them.