If you see (Unavailable for purchase) next to your sale price on all your items, it means that your template is out of date.
You need to update your template to the latest version, or if you're using a custom template, edit the following line in templates/(Your Template)/Panels/ProductDetails.html
<dd style="%%GLOBAL_HidePrice%%"><em class="ProductPrice
VariationProductPrice">%%GLOBAL_ProductPrice%%</em>
%%GLOBAL_IncludingExcludingTax%% %%GLOBAL_YouSave%% <span
class="ProductUnavailableText"
style="%%GLOBAL_HideUnavailableText%%">%%LNG_ProductUnavailableText%%</span></dd>
and change it to
<dd style="%%GLOBAL_HidePrice%%"><em class="ProductPrice
VariationProductPrice">%%GLOBAL_ProductPrice%%</em>
%%GLOBAL_IncludingExcludingTax%% %%GLOBAL_YouSave%%</dd>

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