diff --git a/package.json b/package.json
index 64ac004..8e59ceb 100644
--- a/package.json
+++ b/package.json
@@ -46,4 +46,4 @@
     "typescript": "^5.6.2"
   },
   "version": "0.1.40"
-}
\ No newline at end of file
+}
diff --git a/src/lib/buy/index.tsx b/src/lib/buy/index.tsx
index 6ca1a9b..863e5c6 100644
--- a/src/lib/buy/index.tsx
+++ b/src/lib/buy/index.tsx
@@ -187,7 +187,7 @@ function QuoteAndBuy(props: { options: SfBuyOptions }) {
       if (duration) {
         // If duration is set, calculate end from start + duration
         endsAt = roundEndDate(
-          dayjs(startAt).add(duration, "seconds").toDate(),
+          dayjs(coercedStart).add(duration, "seconds").toDate(),
         );
       } else if (end) {
         endsAt = end;
@@ -535,19 +535,20 @@ export async function placeBuyOrder(options: {
   );
 
   const api = await apiClient();
+  const body = {
+    side: "buy",
+    instance_type: options.instanceType,
+    quantity: options.numberNodes,
+    // round start date again because the user might take a long time to confirm
+    start_at: options.startsAt === "NOW"
+      ? "NOW"
+      : roundStartDate(options.startsAt).toISOString(),
+    end_at: roundEndDate(options.endsAt).toISOString(),
+    price: options.totalPriceInCents,
+    colocate_with: options.colocateWith,
+  } as const;
   const { data, error, response } = await api.POST("/v0/orders", {
-    body: {
-      side: "buy",
-      instance_type: options.instanceType,
-      quantity: options.numberNodes,
-      // round start date again because the user might take a long time to confirm
-      start_at: options.startsAt === "NOW"
-        ? "NOW"
-        : roundStartDate(options.startsAt).toISOString(),
-      end_at: roundEndDate(options.endsAt).toISOString(),
-      price: options.totalPriceInCents,
-      colocate_with: options.colocateWith,
-    },
+    body,
   });
 
   if (!response.ok) {
@@ -622,22 +623,24 @@ type QuoteOptions = {
 export async function getQuote(options: QuoteOptions) {
   const api = await apiClient();
 
-  const { data, error, response } = await api.GET("/v0/quote", {
-    params: {
-      query: {
-        side: "buy",
-        instance_type: options.instanceType,
-        quantity: options.quantity,
-        min_start_date: options.minStartTime === "NOW"
-          ? ("NOW" as const)
-          : options.minStartTime.toISOString(),
-        max_start_date: options.maxStartTime === "NOW"
-          ? ("NOW" as const)
-          : options.maxStartTime.toISOString(),
-        min_duration: options.minDurationSeconds,
-        max_duration: options.maxDurationSeconds,
-      },
+  const params = {
+    query: {
+      side: "buy",
+      instance_type: options.instanceType,
+      quantity: options.quantity,
+      min_start_date: options.minStartTime === "NOW"
+        ? ("NOW" as const)
+        : options.minStartTime.toISOString(),
+      max_start_date: options.maxStartTime === "NOW"
+        ? ("NOW" as const)
+        : options.maxStartTime.toISOString(),
+      min_duration: options.minDurationSeconds,
+      max_duration: options.maxDurationSeconds,
     },
+  } as const;
+
+  const { data, error, response } = await api.GET("/v0/quote", {
+    params,
     // timeout after 600 seconds
     signal: AbortSignal.timeout(600 * 1000),
   });