diff --git a/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs b/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs
index 395a336b4..fd7bdec97 100644
--- a/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs
+++ b/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs
@@ -116,7 +116,12 @@ accountTransactionsReport rspec@ReportSpec{_rsReportOpts=ropts} j thisacctq = it
     -- Additional reportq filtering, such as date filtering, happens down in 
     -- accountTransactionsReportItem, which discards transactions with no matched postings.
     acctJournal =
-          ptraceAtWith 5 (("ts3:\n"++).pshowTransactions.jtxns)
+        -- With most calls we will not require transaction prices past this point, and can get a big
+        -- speed improvement by stripping them early. In some cases, such as in hledger-ui, we still
+        -- want to keep prices around, so we can toggle between cost and no cost quickly. We can use
+        -- the show_costs_ flag to be efficient when we can, and detailed when we have to.
+          (if show_costs_ ropts then id else journalMapPostingAmounts mixedAmountStripPrices)
+        . ptraceAtWith 5 (("ts3:\n"++).pshowTransactions.jtxns)
         -- maybe convert these transactions to cost or value
         . journalApplyValuationFromOpts rspec
         . ptraceAtWith 5 (("ts2:\n"++).pshowTransactions.jtxns)
diff --git a/hledger-lib/Hledger/Reports/PostingsReport.hs b/hledger-lib/Hledger/Reports/PostingsReport.hs
index 234d67047..0e38b5bc6 100644
--- a/hledger-lib/Hledger/Reports/PostingsReport.hs
+++ b/hledger-lib/Hledger/Reports/PostingsReport.hs
@@ -120,6 +120,11 @@ matchedPostingsBeforeAndDuring rspec@ReportSpec{_rsReportOpts=ropts,_rsQuery=q}
         sortOn (postingDateOrDate2 (whichDate ropts))            -- sort postings by date or date2
       . (if invert_ ropts then map negatePostingAmount else id)  -- with --invert, invert amounts
       . journalPostings
+      -- With most calls we will not require transaction prices past this point, and can get a big
+      -- speed improvement by stripping them early. In some cases, such as in hledger-ui, we still
+      -- want to keep prices around, so we can toggle between cost and no cost quickly. We can use
+      -- the show_costs_ flag to be efficient when we can, and detailed when we have to.
+      . (if show_costs_ ropts then id else journalMapPostingAmounts mixedAmountStripPrices)
       $ journalValueAndFilterPostings rspec{_rsQuery=beforeandduringq} j
 
     -- filter postings by the query, with no start date or depth limit
diff --git a/hledger-ui/Hledger/UI/RegisterScreen.hs b/hledger-ui/Hledger/UI/RegisterScreen.hs
index 71ced2ad5..4963c59f5 100644
--- a/hledger-ui/Hledger/UI/RegisterScreen.hs
+++ b/hledger-ui/Hledger/UI/RegisterScreen.hs
@@ -69,6 +69,8 @@ rsInit d reset ui@UIState{aopts=_uopts@UIOpts{uoCliOpts=copts@CliOpts{reportspec
     ropts' = ropts {
         -- ignore any depth limit, as in postingsReport; allows register's total to match accounts screen
         depth_=Nothing
+        -- do not strip prices so we can toggle costs within the ui
+      , show_costs_=True
       -- XXX aregister also has this, needed ?
         -- always show historical balance
       -- , balanceaccum_= Historical