So you’d take:
<input type="hidden" name="price" value="100.00" />
And make it like this:
<input type="hidden" name="price" value="[+phx:mo=`Resellers`:then=`[*product_price:math=`? * .80*]`:else=`[*product_price*]`+]" />
So we’re saying:
[+phx: ... invoke PHx
:mo=`Resellers` ... IF the user is a MEMBER of the RESELLERS web group...
then ... we’re gonna do some stuff...
[*product_price:math=`? * .8`*] ... we’re saying, "output the product price multiplied by 0.8"
else ... if they’re not a Reseller
[*product_price*] ... output the product_price TV or placeholder (depending on whether you’re using a Ditto call or a template or etc.)
Check the PHx wiki page for details about PHx:
http://wiki.modxcms.com/index.php/PHx
If you wanted to set explicit reseller prices rather than doing math to calculate them you could just as easily use another TV instead of the product_price TV with the PHx math modifier.
Make sense? If not, let me know where I lost you.