See attached exported xml file and log from a Google Export as well as pics from the template setup; noticed a few issues as follows:
1. Products are exported multiple times, depending on the number of categories they belong to. e.g. a product belonging to 3 categories will be exported 2x3=6 times, a product belonging to 8 categories will be exported 2x8=16 times etc...
2. basepricewithtax is always 0 (shopper group is set correctly)
3. salesprice doesn't take into account target currency (ECB rates retrieved ok), discount or tax rules. Actual product_currency is correct (GBP, i checked this later), but the price value is not converted.
You may verify actual product prices/pics from the exported SEF url. Shop's base currency is EUR.
just an example:
http://www.quality-tuning.co.uk/universal-stainless-steel-exhaust-tip-round-slant-vw-r32-style-l240-in58.html
In the xml you can see:
<g

<![CDATA[ 0.00 ]]>
</g

<g:sale_price>
<![CDATA[ 42.00 ]]>
</g:sale_price>
See attached image bl202-eu-retail.jpg for the actual setup of the prices.
Noted also that a Custom field title filter exists. Would it be possible to have an additional filter on the value of the custom field?
Rgrds,
Chris